null How to Install a Chimney Liner - Northline Express


How to Install a Chimney Liner

Jun 19th 2020

Chimney liners are all fuel venting systems that are intended for use with heating appliances vented through a masonry chimney. Before installing your chimney liner be sure to perform the following tasks:

  • Clear your chimney of any obstructions and debris.

  • Hire a sweep to clean the chimney for you or clean it yourself.

  • Inspect your chimney. Look for cracked, loose or missing bricks or stones.

  • Measure your chimney. A chimney liner kit that will serve a fireplace needs to have the largest diameter pipe that will fit inside your flue, whereas the liner size required for other fuel burning appliances will be determined by the manufacturer’s specifications and local safety codes.

The basic measurements you need before you select a chimney liner kit are the height of your chimney and the inside dimensions of your existing flue. From the top of your chimney, measure to the top of the fireplace smoke chamber or the connection point for your wood stove or furnace.

For a fireplace, you should have a liner with a cross sectional area no less than one tenth of the area of the fireplace opening. This ten to one ratio is a rule of thumb that can vary depending upon the height of the chimney and other factors.

This is important for 2 reasons:

  • If the liner diameter is too small, your fireplace will not draw well, resulting in smoky fires and smoke-filled rooms

  • If the size of liner that you need for your fireplace is too large to fit inside your existing flue, you may need to repair your clay tile liner rather than inserting a steel liner inside it

Now that you've cleaned and inspected your chimney and figured out which liner kit you need, you can begin installing your liner. Follow these simple guidelines to install your chimney liner system:

Chimney Liner

The advantages to a chimney liner is improved draft by sizing the liner to the appliance, hotter core temperatures, improved safety, easier cleaning, and longevity.

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Chimney liner Installation Guide

The installation of your Chimney Liner Kit has to be done from the top. You might be able to perform the installation alone, however since you will be working on the roof, it is safer to have someone help you. The flexible chimney liner will need to be lowered down the chimney shaft. Using a winch will make navigating the liner down through the chimney a little easier.

Lower the liner slowly to make sure you don't damage it in any way and screw on the top plate at the bottom of the liner to keep it in place and to avoid any smoke from getting into the house from the chimney.

If your chimney lining kit came with a tee, the next step will be to remove a sufficient amount of brick and mortar to allow access for the installation of the tee's snout at the base of the chimney where the heating appliance vent connector attaches the tee to the lining system.  Next, separate the tee from it's snout and attach the tee to the liner with the fasteners provided.

Drop or pull the liner  with the attached tee, without the snout, through the chimney until the tee rests in the base of the chimney where the brick and mortar were previously removed.   Next, attach the snout and place the end-cap on the bottom of the tee with the fasteners provided and attach the pipe connecting the heating appliance to the tees snout.

Seal the area around the tee where the brick and mortar were removed with a furnace cement product.  Using a high temperature silicone product, seal the joints where the snout of the tee connects to the pipes from the heating appliance.  Next, connect the heating appliance vent connector to the tee adapter as per local code and appliance manufacturer's written instructions.

Slide the top plate over the liner and center it on the clay tile.  The top plate seals the top of the chimney and supports the flexible liner. Next, you'll want to mark the outline of the clay tile on the underside of the top plate.  Remove the top plate and trim it to the sized marked.

Trim the liner so that 4" of liner extends above the top of the clay tile.  Apply a wide bead of high-temperature silicone around the top surface of the clay tile.  Place the top plate over the liner and slide down the silicone.  Hold the top plate in place and firmly press to create a good seal.  Screw the four fasteners provided through the 2" collar of the top plate and into the liner.  Be sure not to fasten the screws too tight.

Apply a bead of high temperature  silicone to the inside of the of the top section of the liner and to the lower section of the rain cap. Place the rain cap into the top section of the liner and push down until the bead of the rain cap meets the liner and remove the excess silicone.

The stainless steel rain cap acts as a protective covering or housing for the top of the chimney. The rain cap is intended to prevent birds, rain, snow and other foreign object from entering your chimney or entering your home from the chimney. The stainless steel cap also prevents downdrafts.

Once you have your chimney liner installed, it is strongly advised that you insulate. An insulated chimney not only has a better draft, it also stays cleaner longer. To insulate, pour a mixture of vermiculite and cement down the chimney in between the chimney liner and the chimney stone or brick. This will insulate the chimney, allowing it to heat more quickly, and allowing your stove to heat more effectively.

Chimney Liners are available in single-wall liner kits and smooth-wall liner kits. To see which one is best for you, follow the link below and compare both types of chimney liner.

which chimney liner is best for me